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Sticta herhacea. Grass-Green Lichen 



Also called Lobaria herhacea. This species, rare in the New 

 York area, differs from 6^. amplissima only in being smaller and 

 thinner, and in having spores divided into only 2 cells and measur- 

 ing 26 to 44 by 9 to 11 microns. It should be looked for on tree 

 bark. For general characters and comparisons, see 6*. amplissima. 



Sticta scrohiculata. Warty Leather Lichen 



Also called S. verrucosa or Lobaria scrobiculata. Reaching only 

 the extreme northern limits of the New York area, where it may 

 be looked for on tree-bark or over mosses. The Hchen forms some- 

 what irregular rosettes 15 cm. or more across, but with little- 

 divided, wavy-edged lobes as much as 3 cm. across. The smooth 

 or somewhat pitted upper surface is greenish or yellowish gray, 

 often with gray or bluish dusty warts 1 mm. or so in diameter 

 along the margins and ridges. The under surface, pale to dark 

 brown, is clothed with down, but speckled with chalky white, 

 roundish bare patches up to 2 mm. in diameter. Algal cells in chains 

 (Nostoc). 



Fruits are unknown in this region. 



Sticta scrobiculata differs from ^. amplissima in its much 

 broader lobes, thicker and more leathery texture, but particularly 

 in the white-speckled under surface. All other speckled Leather 

 Lichens are brown, not gray, and the speckles beneath 6^. sylvatica, 

 S. quercizans and 6^. fuliginosa are tiny smooth cups, not mere bare 

 spots. No others have the gray soredia above except 5". pulmonaria 

 which, instead of speckling below, has a pattern of mounds and 

 grooves, with the summits of the mounds often bare, but buff, not 

 white. Nephroma resupinatum, with smaller parts, has white warts 

 on the under surface, but these hardly resemble the flat, white 

 spots of the Sticta. Gray forms of Peltigera polydactyla and P. 

 malacea may appear speckled beneath, but the pale spots are spaces 

 between darkened and thickened veins, and are not bare. Also the 

 enlarged holdfasts of the Peltigera contrast with the small, sparse 

 ones of Sticta. Yet there are forms of Peltigera which when sterile 

 are sometimes mistaken for 6^. scrobiculata. 



